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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * HPMC (High Priority Machine Check) handler.
4 *
5 * Copyright (C) 1999 Philipp Rumpf <prumpf@tux.org>
6 * Copyright (C) 1999 Hewlett-Packard (Frank Rowand)
7 * Copyright (C) 2000 Hewlett-Packard (John Marvin)
8 */
9
10
11/*
12 * This HPMC handler retrieves the HPMC pim data, resets IO and
13 * returns to the default trap handler with code set to 1 (HPMC).
14 * The default trap handler calls handle interruption, which
15 * does a stack and register dump. This at least allows kernel
16 * developers to get back to C code in virtual mode, where they
17 * have the option to examine and print values from memory that
18 * would help in debugging an HPMC caused by a software bug.
19 *
20 * There is more to do here:
21 *
22 * 1) On MP systems we need to synchronize processors
23 * before calling pdc/iodc.
24 * 2) We should be checking the system state and not
25 * returning to the fault handler if things are really
26 * bad.
27 *
28 */
29
30 .level 1.1
31
32#include <asm/assembly.h>
33#include <asm/pdc.h>
34#include <asm/psw.h>
35
36#include <linux/linkage.h>
37#include <linux/init.h>
38
39 /*
40 * stack for os_hpmc, the HPMC handler.
41 * buffer for IODC procedures (for the HPMC handler).
42 *
43 * IODC requires 7K byte stack. That leaves 1K byte for os_hpmc.
44 */
45
46 __PAGE_ALIGNED_BSS
47 .align 4096
48hpmc_stack:
49 .block 16384
50
51#define HPMC_IODC_BUF_SIZE 0x8000
52
53 __PAGE_ALIGNED_BSS
54 .align 4096
55hpmc_iodc_buf:
56 .block HPMC_IODC_BUF_SIZE
57
58 .section .bss
59 .align 8
60hpmc_raddr:
61 .block 128
62
63#define HPMC_PIM_DATA_SIZE 896 /* Enough to hold all architected 2.0 state */
64
65 .section .bss
66 .align 8
67ENTRY(hpmc_pim_data)
68 .block HPMC_PIM_DATA_SIZE
69END(hpmc_pim_data)
70
71 .text
72
73 .import intr_save, code
74 .align 16
75ENTRY(os_hpmc)
76.os_hpmc:
77
78 /*
79 * registers modified:
80 *
81 * Using callee saves registers without saving them. The
82 * original values are in the pim dump if we need them.
83 *
84 * r2 (rp) return pointer
85 * r3 address of PDCE_PROC
86 * r4 scratch
87 * r5 scratch
88 * r23 (arg3) procedure arg
89 * r24 (arg2) procedure arg
90 * r25 (arg1) procedure arg
91 * r26 (arg0) procedure arg
92 * r30 (sp) stack pointer
93 *
94 * registers read:
95 *
96 * r26 contains address of PDCE_PROC on entry
97 * r28 (ret0) return value from procedure
98 */
99
100 copy arg0, %r3 /* save address of PDCE_PROC */
101
102 /*
103 * disable nested HPMCs
104 *
105 * Increment os_hpmc checksum to invalidate it.
106 * Do this before turning the PSW M bit off.
107 */
108
109 mfctl %cr14, %r4
110 ldw 52(%r4),%r5
111 addi 1,%r5,%r5
112 stw %r5,52(%r4)
113
114 /* MP_FIXME: synchronize all processors. */
115
116 /* Setup stack pointer. */
117
118 load32 PA(hpmc_stack),sp
119
120 ldo 128(sp),sp /* leave room for arguments */
121
122 /*
123 * Most PDC routines require that the M bit be off.
124 * So turn on the Q bit and turn off the M bit.
125 */
126
127 ldi PSW_SM_Q,%r4 /* PSW Q on, PSW M off */
128 mtctl %r4,ipsw
129 mtctl %r0,pcsq
130 mtctl %r0,pcsq
131 load32 PA(os_hpmc_1),%r4
132 mtctl %r4,pcoq
133 ldo 4(%r4),%r4
134 mtctl %r4,pcoq
135 rfi
136 nop
137
138os_hpmc_1:
139
140 /* Call PDC_PIM to get HPMC pim info */
141
142 /*
143 * Note that on some newer boxes, PDC_PIM must be called
144 * before PDC_IO if you want IO to be reset. PDC_PIM sets
145 * a flag that PDC_IO examines.
146 */
147
148 ldo PDC_PIM(%r0), arg0
149 ldo PDC_PIM_HPMC(%r0),arg1 /* Transfer HPMC data */
150 load32 PA(hpmc_raddr),arg2
151 load32 PA(hpmc_pim_data),arg3
152 load32 HPMC_PIM_DATA_SIZE,%r4
153 stw %r4,-52(sp)
154
155 ldil L%PA(os_hpmc_2), rp
156 bv (r3) /* call pdce_proc */
157 ldo R%PA(os_hpmc_2)(rp), rp
158
159os_hpmc_2:
160 comib,<> 0,ret0, os_hpmc_fail
161
162 /* Reset IO by calling the hversion dependent PDC_IO routine */
163
164 ldo PDC_IO(%r0),arg0
165 ldo 0(%r0),arg1 /* log IO errors */
166 ldo 0(%r0),arg2 /* reserved */
167 ldo 0(%r0),arg3 /* reserved */
168 stw %r0,-52(sp) /* reserved */
169
170 ldil L%PA(os_hpmc_3),rp
171 bv (%r3) /* call pdce_proc */
172 ldo R%PA(os_hpmc_3)(rp),rp
173
174os_hpmc_3:
175
176 /* FIXME? Check for errors from PDC_IO (-1 might be OK) */
177
178 /*
179 * Initialize the IODC console device (HPA,SPA, path etc.
180 * are stored on page 0.
181 */
182
183 /*
184 * Load IODC into hpmc_iodc_buf by calling PDC_IODC.
185 * Note that PDC_IODC handles flushing the appropriate
186 * data and instruction cache lines.
187 */
188
189 ldo PDC_IODC(%r0),arg0
190 ldo PDC_IODC_READ(%r0),arg1
191 load32 PA(hpmc_raddr),arg2
192 ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg3 /* console hpa */
193 ldo PDC_IODC_RI_INIT(%r0),%r4
194 stw %r4,-52(sp)
195 load32 PA(hpmc_iodc_buf),%r4
196 stw %r4,-56(sp)
197 load32 HPMC_IODC_BUF_SIZE,%r4
198 stw %r4,-60(sp)
199
200 ldil L%PA(os_hpmc_4),rp
201 bv (%r3) /* call pdce_proc */
202 ldo R%PA(os_hpmc_4)(rp),rp
203
204os_hpmc_4:
205 comib,<> 0,ret0,os_hpmc_fail
206
207 /* Call the entry init (just loaded by PDC_IODC) */
208
209 ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg0 /* console hpa */
210 ldo ENTRY_INIT_MOD_DEV(%r0), arg1
211 ldw BOOT_CONSOLE_SPA_OFFSET(%r0),arg2 /* console spa */
212 depi 0,31,11,arg2 /* clear bits 21-31 */
213 ldo BOOT_CONSOLE_PATH_OFFSET(%r0),arg3 /* console path */
214 load32 PA(hpmc_raddr),%r4
215 stw %r4, -52(sp)
216 stw %r0, -56(sp) /* HV */
217 stw %r0, -60(sp) /* HV */
218 stw %r0, -64(sp) /* HV */
219 stw %r0, -68(sp) /* lang, must be zero */
220
221 load32 PA(hpmc_iodc_buf),%r5
222 ldil L%PA(os_hpmc_5),rp
223 bv (%r5)
224 ldo R%PA(os_hpmc_5)(rp),rp
225
226os_hpmc_5:
227 comib,<> 0,ret0,os_hpmc_fail
228
229 /* Prepare to call intr_save */
230
231 /*
232 * Load kernel page directory (load into user also, since
233 * we don't intend to ever return to user land anyway)
234 */
235
236 load32 PA(swapper_pg_dir),%r4
237 mtctl %r4,%cr24 /* Initialize kernel root pointer */
238 mtctl %r4,%cr25 /* Initialize user root pointer */
239
240 /* Clear sr4-sr7 */
241
242 mtsp %r0, %sr4
243 mtsp %r0, %sr5
244 mtsp %r0, %sr6
245 mtsp %r0, %sr7
246
247 tovirt_r1 %r30 /* make sp virtual */
248
249 rsm PSW_SM_Q,%r0 /* Clear Q bit */
250 ldi 1,%r8 /* Set trap code to "1" for HPMC */
251 load32 PA(intr_save),%r1
252 be 0(%sr7,%r1)
253 nop
254
255os_hpmc_fail:
256
257 /*
258 * Reset the system
259 *
260 * Some systems may lockup from a broadcast reset, so try the
261 * hversion PDC_BROADCAST_RESET() first.
262 * MP_FIXME: reset all processors if more than one central bus.
263 */
264
265 /* PDC_BROADCAST_RESET() */
266
267 ldo PDC_BROADCAST_RESET(%r0),arg0
268 ldo 0(%r0),arg1 /* do reset */
269
270 ldil L%PA(os_hpmc_6),rp
271 bv (%r3) /* call pdce_proc */
272 ldo R%PA(os_hpmc_6)(rp),rp
273
274os_hpmc_6:
275
276 /*
277 * possible return values:
278 * -1 non-existent procedure
279 * -2 non-existent option
280 * -16 unaligned stack
281 *
282 * If call returned, do a broadcast reset.
283 */
284
285 ldil L%0xfffc0000,%r4 /* IO_BROADCAST */
286 ldo 5(%r0),%r5
287 stw %r5,48(%r4) /* CMD_RESET to IO_COMMAND offset */
288
289 b .
290 nop
291 .align 16 /* make function length multiple of 16 bytes */
292.os_hpmc_end:
293
294
295 __INITRODATA
296.globl os_hpmc_size
297 .align 4
298 .type os_hpmc_size, @object
299 .size os_hpmc_size, 4
300os_hpmc_size:
301 .word .os_hpmc_end-.os_hpmc
1/*
2 * HPMC (High Priority Machine Check) handler.
3 *
4 * Copyright (C) 1999 Philipp Rumpf <prumpf@tux.org>
5 * Copyright (C) 1999 Hewlett-Packard (Frank Rowand)
6 * Copyright (C) 2000 Hewlett-Packard (John Marvin)
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
11 * any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23
24/*
25 * This HPMC handler retrieves the HPMC pim data, resets IO and
26 * returns to the default trap handler with code set to 1 (HPMC).
27 * The default trap handler calls handle interruption, which
28 * does a stack and register dump. This at least allows kernel
29 * developers to get back to C code in virtual mode, where they
30 * have the option to examine and print values from memory that
31 * would help in debugging an HPMC caused by a software bug.
32 *
33 * There is more to do here:
34 *
35 * 1) On MP systems we need to synchronize processors
36 * before calling pdc/iodc.
37 * 2) We should be checking the system state and not
38 * returning to the fault handler if things are really
39 * bad.
40 *
41 */
42
43 .level 1.1
44
45#include <asm/assembly.h>
46#include <asm/pdc.h>
47#include <asm/psw.h>
48
49#include <linux/linkage.h>
50#include <linux/init.h>
51
52 /*
53 * stack for os_hpmc, the HPMC handler.
54 * buffer for IODC procedures (for the HPMC handler).
55 *
56 * IODC requires 7K byte stack. That leaves 1K byte for os_hpmc.
57 */
58
59 __PAGE_ALIGNED_BSS
60 .align 4096
61hpmc_stack:
62 .block 16384
63
64#define HPMC_IODC_BUF_SIZE 0x8000
65
66 __PAGE_ALIGNED_BSS
67 .align 4096
68hpmc_iodc_buf:
69 .block HPMC_IODC_BUF_SIZE
70
71 .section .bss
72 .align 8
73hpmc_raddr:
74 .block 128
75
76#define HPMC_PIM_DATA_SIZE 896 /* Enough to hold all architected 2.0 state */
77
78 .section .bss
79 .align 8
80ENTRY(hpmc_pim_data)
81 .block HPMC_PIM_DATA_SIZE
82END(hpmc_pim_data)
83
84 .text
85
86 .import intr_save, code
87 .align 16
88ENTRY_CFI(os_hpmc)
89.os_hpmc:
90
91 /*
92 * registers modified:
93 *
94 * Using callee saves registers without saving them. The
95 * original values are in the pim dump if we need them.
96 *
97 * r2 (rp) return pointer
98 * r3 address of PDCE_PROC
99 * r4 scratch
100 * r5 scratch
101 * r23 (arg3) procedure arg
102 * r24 (arg2) procedure arg
103 * r25 (arg1) procedure arg
104 * r26 (arg0) procedure arg
105 * r30 (sp) stack pointer
106 *
107 * registers read:
108 *
109 * r26 contains address of PDCE_PROC on entry
110 * r28 (ret0) return value from procedure
111 */
112
113 copy arg0, %r3 /* save address of PDCE_PROC */
114
115 /*
116 * disable nested HPMCs
117 *
118 * Increment os_hpmc checksum to invalidate it.
119 * Do this before turning the PSW M bit off.
120 */
121
122 mfctl %cr14, %r4
123 ldw 52(%r4),%r5
124 addi 1,%r5,%r5
125 stw %r5,52(%r4)
126
127 /* MP_FIXME: synchronize all processors. */
128
129 /* Setup stack pointer. */
130
131 load32 PA(hpmc_stack),sp
132
133 ldo 128(sp),sp /* leave room for arguments */
134
135 /*
136 * Most PDC routines require that the M bit be off.
137 * So turn on the Q bit and turn off the M bit.
138 */
139
140 ldi PSW_SM_Q,%r4 /* PSW Q on, PSW M off */
141 mtctl %r4,ipsw
142 mtctl %r0,pcsq
143 mtctl %r0,pcsq
144 load32 PA(os_hpmc_1),%r4
145 mtctl %r4,pcoq
146 ldo 4(%r4),%r4
147 mtctl %r4,pcoq
148 rfi
149 nop
150
151os_hpmc_1:
152
153 /* Call PDC_PIM to get HPMC pim info */
154
155 /*
156 * Note that on some newer boxes, PDC_PIM must be called
157 * before PDC_IO if you want IO to be reset. PDC_PIM sets
158 * a flag that PDC_IO examines.
159 */
160
161 ldo PDC_PIM(%r0), arg0
162 ldo PDC_PIM_HPMC(%r0),arg1 /* Transfer HPMC data */
163 load32 PA(hpmc_raddr),arg2
164 load32 PA(hpmc_pim_data),arg3
165 load32 HPMC_PIM_DATA_SIZE,%r4
166 stw %r4,-52(sp)
167
168 ldil L%PA(os_hpmc_2), rp
169 bv (r3) /* call pdce_proc */
170 ldo R%PA(os_hpmc_2)(rp), rp
171
172os_hpmc_2:
173 comib,<> 0,ret0, os_hpmc_fail
174
175 /* Reset IO by calling the hversion dependent PDC_IO routine */
176
177 ldo PDC_IO(%r0),arg0
178 ldo 0(%r0),arg1 /* log IO errors */
179 ldo 0(%r0),arg2 /* reserved */
180 ldo 0(%r0),arg3 /* reserved */
181 stw %r0,-52(sp) /* reserved */
182
183 ldil L%PA(os_hpmc_3),rp
184 bv (%r3) /* call pdce_proc */
185 ldo R%PA(os_hpmc_3)(rp),rp
186
187os_hpmc_3:
188
189 /* FIXME? Check for errors from PDC_IO (-1 might be OK) */
190
191 /*
192 * Initialize the IODC console device (HPA,SPA, path etc.
193 * are stored on page 0.
194 */
195
196 /*
197 * Load IODC into hpmc_iodc_buf by calling PDC_IODC.
198 * Note that PDC_IODC handles flushing the appropriate
199 * data and instruction cache lines.
200 */
201
202 ldo PDC_IODC(%r0),arg0
203 ldo PDC_IODC_READ(%r0),arg1
204 load32 PA(hpmc_raddr),arg2
205 ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg3 /* console hpa */
206 ldo PDC_IODC_RI_INIT(%r0),%r4
207 stw %r4,-52(sp)
208 load32 PA(hpmc_iodc_buf),%r4
209 stw %r4,-56(sp)
210 load32 HPMC_IODC_BUF_SIZE,%r4
211 stw %r4,-60(sp)
212
213 ldil L%PA(os_hpmc_4),rp
214 bv (%r3) /* call pdce_proc */
215 ldo R%PA(os_hpmc_4)(rp),rp
216
217os_hpmc_4:
218 comib,<> 0,ret0,os_hpmc_fail
219
220 /* Call the entry init (just loaded by PDC_IODC) */
221
222 ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg0 /* console hpa */
223 ldo ENTRY_INIT_MOD_DEV(%r0), arg1
224 ldw BOOT_CONSOLE_SPA_OFFSET(%r0),arg2 /* console spa */
225 depi 0,31,11,arg2 /* clear bits 21-31 */
226 ldo BOOT_CONSOLE_PATH_OFFSET(%r0),arg3 /* console path */
227 load32 PA(hpmc_raddr),%r4
228 stw %r4, -52(sp)
229 stw %r0, -56(sp) /* HV */
230 stw %r0, -60(sp) /* HV */
231 stw %r0, -64(sp) /* HV */
232 stw %r0, -68(sp) /* lang, must be zero */
233
234 load32 PA(hpmc_iodc_buf),%r5
235 ldil L%PA(os_hpmc_5),rp
236 bv (%r5)
237 ldo R%PA(os_hpmc_5)(rp),rp
238
239os_hpmc_5:
240 comib,<> 0,ret0,os_hpmc_fail
241
242 /* Prepare to call intr_save */
243
244 /*
245 * Load kernel page directory (load into user also, since
246 * we don't intend to ever return to user land anyway)
247 */
248
249 load32 PA(swapper_pg_dir),%r4
250 mtctl %r4,%cr24 /* Initialize kernel root pointer */
251 mtctl %r4,%cr25 /* Initialize user root pointer */
252
253 /* Clear sr4-sr7 */
254
255 mtsp %r0, %sr4
256 mtsp %r0, %sr5
257 mtsp %r0, %sr6
258 mtsp %r0, %sr7
259
260 tovirt_r1 %r30 /* make sp virtual */
261
262 rsm PSW_SM_Q,%r0 /* Clear Q bit */
263 ldi 1,%r8 /* Set trap code to "1" for HPMC */
264 load32 PA(intr_save),%r1
265 be 0(%sr7,%r1)
266 nop
267
268os_hpmc_fail:
269
270 /*
271 * Reset the system
272 *
273 * Some systems may lockup from a broadcast reset, so try the
274 * hversion PDC_BROADCAST_RESET() first.
275 * MP_FIXME: reset all processors if more than one central bus.
276 */
277
278 /* PDC_BROADCAST_RESET() */
279
280 ldo PDC_BROADCAST_RESET(%r0),arg0
281 ldo 0(%r0),arg1 /* do reset */
282
283 ldil L%PA(os_hpmc_6),rp
284 bv (%r3) /* call pdce_proc */
285 ldo R%PA(os_hpmc_6)(rp),rp
286
287os_hpmc_6:
288
289 /*
290 * possible return values:
291 * -1 non-existent procedure
292 * -2 non-existent option
293 * -16 unaligned stack
294 *
295 * If call returned, do a broadcast reset.
296 */
297
298 ldil L%0xfffc0000,%r4 /* IO_BROADCAST */
299 ldo 5(%r0),%r5
300 stw %r5,48(%r4) /* CMD_RESET to IO_COMMAND offset */
301
302 b .
303 nop
304 .align 16 /* make function length multiple of 16 bytes */
305ENDPROC_CFI(os_hpmc)
306.os_hpmc_end:
307
308
309 __INITRODATA
310.globl os_hpmc_size
311 .align 4
312 .type os_hpmc_size, @object
313 .size os_hpmc_size, 4
314os_hpmc_size:
315 .word .os_hpmc_end-.os_hpmc